Preparing a format of Calibration of weighing balance in Plant and store area

Which criteria / measuring parameters should in calibration of weighing balance in Plant and store area ? plz guide me…I am going to prepare format for verification and calibration format… so, plz help me …

the balance having capacity of (1) 50 kg, (2) 60 kg, (3) 600 kgs…for this three type balance capacity I want to prepare the calibration format…

Refer SOP for Balance Calibration

Whether Electronic balance comes under instrument or equipment??